Heretofore, medical treatment of inserting a catheter into a blood vessel to excise an atheroma generated in the blood vessel has been performed. An analysis of whether or not an atheroma is generated in a blood vessel has been performed by inserting a catheter having an ultrasound probe into the blood vessel to obtain an ultrasonic image. Moreover, for the analysis of whether or not an atheroma is present in a blood vessel, image analysis by an optical coherence tomography (hereinafter also referred to as “OCT”), for example, can be conducted (Patent Literature 4).
In order to excise an atheroma found in a blood vessel, an atheroma excision catheter has been used which excises an atheroma with a cutter through an opening in the side wall. The atheroma excision catheter is inserted into a blood vessel to the position where an opening faces the atheroma, and then a balloon provided in the vicinity of the opening is expanded, so that the opening is brought close to the atheroma, so that the atheroma enters a lumen of the atheroma excision catheter through the opening. In the lumen of the atheroma excision catheter, a cutter is movably provided in the axial direction. The cutter receives drive transmitted from a motor to be rotated in the lumen. The cutter is moved in the lumen while being rotated to thereby excise the atheroma entering the lumen. The excised atheroma is accommodated in the lumen of the atheroma excision catheter (Patent Literatures 1 and 2).
In the excision of the atheroma described above, ultrasonic images are obtained immediately before the excision in order to align the positions of the atheroma and the opening of the atheroma excision catheter. Thereafter, the atheroma is excised by the atheroma excision catheter. Furthermore, ultrasonic images are obtained again in order to check the state of the blood vessel after the excision of the atheroma. When it is temporarily judged that the atheroma is not sufficiently excised, the remaining atheroma is excised again by the atheroma excision catheter, and thereafter the state of the blood vessel is checked again. In such an operation, the catheter having the ultrasound probe and the atheroma excision catheter are alternately inserted into the blood vessel, which is likely to complicate the operation. In view of such circumstances, a catheter has been devised in which an atheroma excision catheter is provided with an ultrasound probe capable of rotating around the axis (Patent Literature 3).